DTU iGEM Team 2018: Building Mycotextures

The team won a bronze medal for their project.

 The team attended or hosted the following events in 2018:

  • BioBrick Tutorial (Hosted the event)
  • Nordic iGEM Conference
  • Science in forum

The team was fortunate enough to have received grants from the contributors listed below. Without their economic support, we wouldn't have been able to afford working on this project.

Project

The DTU BioBuilders worked to develop a toolbox so properties of fungi could be manipulated and exploited to build fungal materials.

Background

Mars has become the new goal in the international space race of this century. Unlike earlier space races, the goal is no longer to simply get there but has expanded into also staying there. This goal can further be seen as the pilot project for settlements in other parts of space and is a key step for humanity to become a multi-planetary species. Decades of research and technological advances are beginning to show that extraterrestrial colonisation may soon be possible, and interest from private companies like SpaceX is fuelling this new space race. 

One of the major pressing questions, when it comes to colonising of Mars, is the matter of obtaining building materials to build the initial colony. Broadly speaking, there are two approaches to this problem: Either bring the materials from Earth or use the resources already on Mars. This first option requires escaping the gravitational pull of Earth, which is not a cheap feat. The astronomical costs affiliated with the first option gives voice to solutions focusing on the use of local resources on Mars. Our project tries to explore the second option of using the raw materials available to bring the mission of colonising Mars closer to reality. Our suggestion is to use mycotecture (fungal-based building material) to construct the structure, as the fungus can be grown on Mars. The fungus can be engineered here on Earth and transported as spores in the spacecraft, thereby mostly removing the cost of transportation. For economical purposes, we have planned for the final substrate on Mars to be cyanobacteria as they produce O2 from carbon dioxide and can function as a carbon source.

The extreme environment on Mars makes it very hostile compared to on Earth. Extreme cold, high radiation, and very thin atmosphere does not make it an easy task to build nor to live on Mars. We have looked into protecting humans and materials by introducing melanin into the biomaterials, which builds on the work of the Stanford Brown 2016 team. We have also worked on improving the growth and structural strength of the final materials by experimentally testing several fungal candidates, growth conditions and many different substrates. We have also worked with the gene gfaA to improve the structural strength of the mycotecture as well as the gene amilCP to introduce color changes in our materials. 

In our project, we chose to primarily work with Aspergillus oryzae as working with Schizophyllum commune and Pleurotus ostreatus proved to be too difficult and time-consuming both in regard to genetic manipulation and growth, for which reason all of the synthetic biology was done in DH5-α E. coli.

Parallel to the wetlab work, a lot of effort has been put into making different models. These modeling efforts have led to two growth models and a mechanical model of the structural integrities using the COMSOL® modeling software. The first of the growth models predict phenotypic growth behavior of fungal colonies by simulating hyphal branching patterns. The other uses a set of partial differential equations to describe the density distribution of fungus considering parameters such as substrate concentration. The final project design, which is made to be easily producible on Mars, utilizes two assemblable triangular planes which can form geodesic domes. The structural integrity of these domes have been simulated with a mechanical model using experimental data based on our fungal materials measured by industrial grade equipment at DTU as well as equipment of our own design. 

We are not the first movers when it comes to the production of mycotectures. We have sought out the Green Island, NY-based company Ecovative Design for guidance. They have been extremely helpful in determining growth and baking conditions, as well as sharing their protoplasting protocol and the Ganoderma resinaceum strain, when producing the bricks.

In the iGEM spirit of sharing knowledge and working together, we have eagerly sought out opportunities to create awareness and collaborate with other iGEM teams. In the spring we hosted a 3-day workshop for the Nordic iGEM teams, we started a high school iGEM team, we collaborated with the universities of Copenhagen and Exeter to compose a report on space travel and much more. The shape of our project is not purely of our own making, and we ought to thank Stanford-Brown-RISD team and their supervisor, Dr. Lynn Rothschild, for helping shape the initial ideas of our project and the subsequent sparring on our ideas that has helped lead us towards our final design.

Read more on their iGEM homepage.